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STM32F4: ADC1 + EXTI11 binding problem

keaven
Associate II
Posted on December 05, 2014 at 17:27

Dear all,

I need to use the external trigger with ADC1 but I am not able to do it. I have done my code in step. I did make work my ADC1 with TIM2 as internal triggered. That worked well. Then I have I have generated a PWM on port PB7 with timer 4 , that worked well. I used the pin PC11 as input and use the PWM to trigger the interrupt routine correctly. Now , I need to use that trigger as input trigger for my ADC1 but I cannot can get it work properly. I must missed a configuration step to link the two together. I put my code below to see if you can pointed it out. Note that I am using also the DMA to acquire 2048 converted values. (that is working well with the internal timer trigger) Thanks in advance to all.

void DoADCConversion (void)
{
//ADC Conversion
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
EXTI_InitTypeDef EXTI_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
 uint32_t PeriodCounter = (90000000 / 1500000); 1.5 MHz based on 90MHz
//Clock Enable
//Ouput IO for timing PA & PG
//Analog Input and DMA2
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA | RCC_AHB1Periph_GPIOB |
RCC_AHB1Periph_GPIOC | RCC_AHB1Periph_DMA2 |
RCC_AHB1Periph_GPIOG, ENABLE);
//ADC1
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
//TIMER4
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
/* Configure PG6 in output pushpull mode */
/* Global Acquisition Time */
GPIO_StructInit(&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOG, &GPIO_InitStructure);
/* Conversion Time */
GPIO_StructInit(&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);
//Configure ADC3 Channel13 pin as analog input
GPIO_StructInit(&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
GPIO_Init(GPIOC, &GPIO_InitStructure);
//PC11 for external trigger
GPIO_StructInit(&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
GPIO_Init(GPIOC, &GPIO_InitStructure);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOC, EXTI_PinSource11);
//EXTI Configuration Line 11
EXTI_DeInit();
EXTI_StructInit(&EXTI_InitStructure);
EXTI_InitStructure.EXTI_Line = EXTI_Line11;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
//PWM
GPIO_StructInit(&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_TIM4);
//Time base configuration
TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
TIM_TimeBaseStructure.TIM_Period = (PeriodCounter- 1);
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);
// PWM1 Mode configuration: Timer 4 Channel 2
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = ((PeriodCounter / 2) - 1);
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC2Init(TIM4, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM4, TIM_OCPreload_Enable);
// TIM2 enable counter
TIM_Cmd(TIM4, ENABLE);
// DMA2 Stream0 channel2 configuration
DMA_DeInit(DMA2_Stream0); //Reset DMA to default values
DMA_InitStructure.DMA_Channel = DMA_Channel_0;
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)ADC1_DR_ADDRESS;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)&ADCxConvertedValue[0];
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = 2140;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_Init(DMA2_Stream0, &DMA_InitStructure);
DMA_ITConfig(DMA2_Stream0, DMA_IT_TC, ENABLE);
DMA_Cmd(DMA2_Stream0, ENABLE);
//ADC Common Init
ADC_CommunStructure.ADC_Prescaler = ADC_Prescaler_Div2;
ADC_CommunStructure.ADC_Mode = ADC_Mode_Independent;
//DMA Mode for multi ADC
ADC_CommunStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;
//Delay in between two sampling
ADC_CommunStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;
ADC_CommonInit(&ADC_CommunStructure);
//Init ADC1
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
//Group channel scan
ADC_InitStructure.ADC_ScanConvMode = DISABLE;
//Single or Continuous
ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_RisingFalling;
ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_Ext_IT11;;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
//Number of conversion in group
ADC_InitStructure.ADC_NbrOfConversion = 1;
ADC_Init(ADC1, &ADC_InitStructure);
// Enable ADC1 DMA
ADC_DMACmd(ADC1, ENABLE);
// ADC1 regular channel3 configuration
ADC_RegularChannelConfig(ADC1, ADCx_CHANNEL, 1, ADC_SampleTime_3Cycles);
// Enable DMA request after last transfer (Single-ADC mode)
ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);
ADC_Cmd(ADC1, ENABLE);
GPIOG->BSRRL = GPIO_Pin_6;
ADC_SoftwareStartConv(ADC1);
//Wait for end of transfer
while(DMA_GetFlagStatus(DMA2_Stream0, DMA_FLAG_TCIF0) == RESET);
GPIOG->BSRRH = GPIO_Pin_6;
DMA_ClearFlag(DMA2_Stream0, DMA_FLAG_TCIF0);
return;
}

#stm32f4-adc-exti11
6 REPLIES 6
Posted on December 05, 2014 at 17:45

ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigInjecConvEdge_RisingFalling;

Injected? you sure?
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keaven
Associate II
Posted on December 05, 2014 at 17:53

I had to say, you have the eye !

I did some changes regarding the EXTI_Mode too , used EXTI_Mode_Interrupt instead to EXTI_Mode_Event.

But once I changed for the right value for ADC_ExternalTrigConvEdge , it worked as expected.

Thanks a lot would have take some time to see that .

Keaven

keaven
Associate II
Posted on December 05, 2014 at 22:01

Quick question.

The code run great on one pass. I tried to spit it so I can start a single acquisition on a function call. My assumption was to only take out this part ..

ADC_Cmd(ADC1, ENABLE);
GPIOG->BSRRL = GPIO_Pin_6;
ADC_SoftwareStartConv(ADC1);
//Wait for end of transfer
while(DMA_GetFlagStatus(DMA2_Stream0, DMA_FLAG_TCIF0) == RESET);
GPIOG->BSRRH = GPIO_Pin_6;
DMA_ClearFlag(DMA2_Stream0, DMA_FLAG_TCIF0);

Looks like I am wrong because the DMA Flag is not raised on the second pass but I cleared it. Which other command I need to call each time? Thank you
Posted on December 05, 2014 at 22:46

I've got a rather narrow field of view on this code, I would generally double the buffer size and use the HT and TC DMA interrupts to manage alternating halves of the buffer.

DMA_InitStructure.DMA_BufferSize = 2140;

Was this supposed to be 2048 samples? I don't tend to sit in loops polling DMA status, and generally would set up the ADC and DMA once, and then leave it alone.
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keaven
Associate II
Posted on December 08, 2014 at 15:55

Clive1,

No my buffer was exactly the same size of the data required.  This is a CCD sensor .  I understand it is better to let it run but I need to synchronize the the DMA transfer in time.  So to understand well the process, I did it by polling the flag and try to do on request with a press of the button.

My question is now what is required to end properly the process and restart it?  Even, if I let run my transfer/conversion I will have to synchronize the data convert/transfert at exactly every 1 ms once requested randomly in time.

Thanks

keaven
Associate II
Posted on December 08, 2014 at 23:33

Here is how I fixed my problem.

1- I changed the DMA_mode to DMA_Mode_Circular

2- Include ADC_DMACmd(ADC1, ENABLE) inside my function to do a capture

3- Include ADC_DMACmd(ADC1, DISABLE) after clearing my DMA_FLAG_TCIF0 flag to keep my buffer intact.

Add a call to my function on the user button and it works correctly.

Thanks for your help